11/12/2023 0 Comments Mysql create view set variable issue![]() I’ll show the query generated for the different user combinations Select * from cities where country_id in ($mylist) Now, let’s try to use this variable, that I called “mylist” for the demo, in a SQL statement: So I’ve created the Grafana variable with this query, and selected “Multi-value” and “Include All option” to let the user chose any combination: I alias my columns with “_value” and “_text” to show the country name to the user but get the country code from what she selected. Select country_id _value, name _text from countries order by 2 My goal is to get something like that where I can choose one, many, all or no country at all: The problem to solve: IN() list in SQL from a multi-value variableįor this example I’ve created a PostgreSQL database in Google Cloud SQL, loaded sample data from Gerald Venzl and a free grafana cloud service. However, when I find a workaround, I publish it to help others and hopefully find someone who has a better solution, so please leave a comment if what I do there is completely silly. ![]() Yes, Grafana is nice but is very far from what I can do with Excel in 5 minutes. And I’m actually spending more time in finding workarounds than solving problems. When I have a problem, I find the solution (blog posts, forums, mailing lists, support notes)… But with modern software, the first problems I encounter have a dead end in unresolved git issues. I’m working for years with technology that works. If you want to build a dashboard for your boss, or put it on a large screen in the open space, that’s beautiful. Pros: it is really nice, I mean aesthetically. Another way to differentiate GLOBAL and SESSION system variables is to use a second prefix: global or session.I’ve recently looked at Grafana. System variables can be identified using a double sign as a prefix or using the words GLOBAL or SESSION in the SET statement. But their values can be modified within an SQL script. To do so, you can use the command line or include the SET statement in an option file. System variables are usually set at server startup. There is a third type of variable called system variables used to store values that affect individual client connections ( SESSION variables) or affect the entire server operation ( GLOBAL variables). The local variable factor is used to store a decimal value used to multiply the resulting price. That variable is later used in the SELECT statement to multiply the ListPrice field obtained from the table. In the previous example, the variable itemcount is used as a parameter to pass a value to the procedure. 45 SELECT PartNo, Description, itemcount * factor * ListPrice FROM Catalogue END $$ DELIMITER DELIMITER $$ CREATE PROCEDURE GetUpdatedPrices(itemcount INT) BEGIN DECLARE factor DECIMAL( 5, 2) SET factor: = 3.
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